Solution-Processed Ultrathin SnS₂–Pt Nanoplates for Photoelectrochemical Water Oxidation

Abstract

Tin disulfide (SnS₂) is attracting significant interest because of the abundance of its elements and its excellent optoelectronic properties in part related to its layered structure. In this work, we specify the preparation of ultrathin SnS₂ nanoplates (NPLs) through a hot-injection solution-based process. Subsequently, Pt was grown on their surface via in situ reduction of a Pt salt. The photoelectrochemical (PEC) performance of such nanoheterostructures as photoanode toward water oxidation was tested afterwards. Optimized SnS₂-Pt photoanodes provided significantly higher photocurrent densities than bare SnS₂ and SnS₂-based photoanodes of previously reported study. Mott-Schottky analysis and PEC impedance spectroscopy (PEIS) were used to analyze in more detail the effect of Pt on the PEC performance. From these analyses, we attribute the enhanced activity of SnS₂-Pt photoanodes reported here to a combination of the very thin SnS₂ NPLs and the proper electronic contact between Pt nanoparticles (NPs) and SnS₂.